There are significant therapeutic advantages for continuously monitoring analyte levels such as glucose levels of diabetic patients. Commercially available continuous glucose monitoring systems use analyte sensors that detect the glucose levels of the patients for a predetermined time period. During this time period, the analyte sensor is generally required to be periodically calibrated with a blood glucose measurement using, for example, an in vitro blood glucose meter.
Calibration of an analyte sensor typically follows a calibration schedule over the life of the analyte sensor, and are intended to maintain the accuracy of the analyte sensor during its useful life. Each calibration routine requires analysis of data from the analyte sensor in conjunction with a reference value, such as from a finger prick test using a lancing device in conjunction with a conventional blood glucose meter. While other areas of the body may be used to perform the blood glucose measurement, such measurement typically requires drawing a blood sample from the patient and applying the blood sample to a blood glucose test strip. This is often a painful experience, which must be performed periodically based on the calibration schedule of the analyte sensor.